The reasons for the wastage vary. In poor countries it’s due to inefficient farming, bad transport links, and a lack of refrigeration. In wealthier parts of the world it’s down to consumer pickiness. Supermarkets in the U.S. and Britain reject almost a third of fruit and vegetables, which are perfectly edible, just because they don’t look appealing.

American and British households then throw away up to half the food they’ve purchased.

Tim Fox, one of the authors of the report, says the world cannot afford this waste when there are going to be so many more mouths to feed:

“As the global population moves towards 9.5 billion later this century, we’re very concerned about how we’re going to feed that population," says Fox. "Clearly cutting down on this waste of food could go a very long way to meeting that need.”

Fox says this is not just a matter of saving food. Food production uses a lot of energy. If Britain eliminated its household wastage alone, it would save as much fuel as if it had taken 20 percent of its cars off the road.